As for grass-fed vs. grain-fed, most of the arguments seem to center around omega-3, omega-6 ratios. The difference between grass-fed and grain-fed are negligible when you compare them to chicken and pork, let alone nuts and vegetable oils. If I could afford grass-fed beef, I'd eat it, but I think grain-fed beef is fine, especially in the United States. If anything, it has more marbling, so yum! For what it's worth, the Bear argued there was little difference nutritionally and that it had more to do with texture and flavor.
As for grass-fed vs. grain-fed, most of the arguments seem to center around omega-3, omega-6 ratios. The difference between grass-fed and grain-fed are negligible when you compare them to chicken and pork, let alone nuts and vegetable oils. If I could afford grass-fed beef, I'd eat it, but I think grain-fed beef is fine, especially in the United States. If anything, it has more marbling, so yum! For what it's worth, the Bear argued there was little difference nutritionally and that it had more to do with texture and flavor.